A novel frequency support strategy for VSC-HVDC system with large wind power integration

Abstract

In the context of carbon neutralization, wind farms with abundant wind energy will develop fast to replace the traditional thermal power units. In addition, the voltage source converter based high voltage direct current (VSC-HVDC) technology is a promising way to integrate and transmit wind power. However, with the increasing penetration rate of wind power, the frequency stability problem of the new power system will become prominent. To tackle this problem, this paper proposes a novel frequency support strategy for VSC-HVDC system with large wind power integration. Firstly, the virtual inertia control of VSC-HVDC is studied to provide active power support fast by extracting energy from the parallel capacitors of the VSC. Secondly, the frequency-based speed control of the wind turbines is proposed to balance the mismatched power. Moreover, the recovery control of the VSC-HVDC and the wind turbines are discussed. Finally, simulations of a VSC-HVDC with large wind power integration have been conducted in PSCAD/EMTDC to validate the effectiveness of the proposed strategy.